The most recent Intergovernmental Panel on Climate Change assessment report concludes that the Atlantic Meridional Overturning Circulation (AMOC) could weaken substantially but is very unlikely to collapse in the 21st century. However, the assessment largely neglected Greenland Ice Sheet (GrIS) mass loss, lacked a comprehensive uncertainty analysis, and was limited to the 21st century. Here in a community effort, improved estimates of GrIS mass loss are included in multicentennial projections using eight state-of-the-science climate models, and an AMOC emulator is used to provide a probabilistic uncertainty assessment. We find that GrIS melting affects AMOC projections, even though it is of secondary importance. By years 2090-2100, the AMOC weakens by 18% [-3%, -34%; 90% probability] in an intermediate greenhouse-gas mitigation scenario and by 37% [-15%, -65%] under continued high emissions. Afterward, it stabilizes in the former but continues to decline in the latter to -74% [+4%, -100%] by 2290-2300, with a 44% likelihood of an AMOC collapse. This result suggests that an AMOC collapse can be avoided by CO2 mitigation.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/622754 |
| Date | 16 December 2016 |
| Creators | Bakker, P., Schmittner, A., Lenaerts, J. T. M., Abe-Ouchi, A., Bi, D., van den Broeke, M. R., Chan, W.-L., Hu, A., Beadling, R. L., Marsland, S. J., Mernild, S. H., Saenko, O. A., Swingedouw, D., Sullivan, A., Yin, J. |
| Contributors | Univ Arizona, Dept Geosci, College or Earth, Ocean, and Atmospheric Sciences; Oregon State University; Corvallis Oregon USA, College or Earth, Ocean, and Atmospheric Sciences; Oregon State University; Corvallis Oregon USA, Institute for Marine and Atmospheric research; Utrecht University; Utrecht Netherlands, Atmosphere and Ocean Research Institute; University of Tokyo; Tokyo Japan, CSIRO Oceans and Atmosphere; Aspendale Victoria Australia, Institute for Marine and Atmospheric research; Utrecht University; Utrecht Netherlands, Atmosphere and Ocean Research Institute; University of Tokyo; Tokyo Japan, National Center for Atmospheric Research; Boulder Colorado USA, Department of Geosciences; University of Arizona; Tucson Arizona USA, CSIRO Oceans and Atmosphere; Aspendale Victoria Australia, Faculty of Engineering and Science; Sogn og Fjordane University College; Sogndal Norway, Canadian Centre for Climate Modelling and Analysis; Victoria British Columbia Canada, Institut Pierre-Simon Laplace; Paris France, CSIRO Oceans and Atmosphere; Aspendale Victoria Australia, Department of Geosciences; University of Arizona; Tucson Arizona USA |
| Publisher | AMER GEOPHYSICAL UNION |
| Source Sets | University of Arizona |
| Language | English |
| Detected Language | English |
| Type | Article |
| Rights | ©2016. American Geophysical Union and Her Majesty The Queen in Right of Canada. |
| Relation | http://doi.wiley.com/10.1002/2016GL070457 |
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